Phylogenetic study of Iris plants in China based on chloroplast matK gene and nuclear ITS gene

Using both Neighbor-Joining and Maximum Likelihood algorithms, the ITS and matK sequences of Iris species in China were sequenced to explore the phylogenetic relationships of the six subgenera of Iris in China. After alignment of the ITS and matK sequences, a total of 893 characters were obtained for the ITS sequence, with a length variation range of 704–824 bp and 890 characters for the matK sequence, with a length variation range of 865–887 bp. The clustering analysis results were generally consistent with the subgenus classification of Iris species in China. Results suggested Subgen. Iris has a relatively complex phylogenetic relationship within the genus, and further research is needed to refine the internal classifications. Subgen. Limniris is resolved as polyphyletic and the phylogenetic relationships are quite complex. Subgen. Nepalensis is a relatively natural taxonomic group. Subgen. Crossiris is an unnatural taxonomic group. It is recommended to remove Subgen. Xyridion from the Iris classification system and to redefine the Belamcanda chinensis as a species within Subgen. Pardanthopsis of the Iris genus.